Hydrofluoric acid in the SMFL represents a special danger in that it is a toxic. Death can and has occurred from exposure to hydrofluoric acid. The danger arises from the fluorine ion which reacts with the body's calcium to interfere with the transmission of nervous signals, proper functioning of muscles, and electrochemical imbalance. Concentrated hydrofluoric acid represents the greatest danger of fluorine poisoning, but there are other solutions in the SMFL that also represent a fluorine poisoning hazard.

*Special precautions are needed for the safe handling of HF, NH4F, BOE, Pad Etch and Freckle Etch. They should all be considered as toxic and should never come in contact with the users skin.
*Immediate treatment is required should this occur.

*Piranha solutions are very exothermic when mixed, rapidly heating to over 100C in a short period.

*Safety Reminders For Use of Sulfuric Acid/Hydrogen Peroxide Mixtures
**It is difficult to dispose of piranha because the waste continues to react and decompose for a long period of time. This builds up pressure in the waste bottles, causing them to burst.
**Commercially stabilized versions of Piranha are available such as Nanostrip (http//www.cyantek.com/htm/nano-strip.htm).
**Personal protective equipment is always required when working with piranha solutions .
**Whenever handling Piranha, only use glass containers, preferably Pyrex.

**In preparing a Piranha solution, add hydrogen peroxide to the sulfuric acid - slowly!
***Piranha solution is very energetic and potentially explosive. When being made it is very likely to become hot, more than 100 degrees C. Handle with care.
***Substrates should be rinsed and dried before placing them in a piranha bath. Piranhas are used to remove residues of photoresist and acetone, not the compounds themselves.
***Adding any acids or bases to piranha or spraying it with water will accelerate the reaction. This includes some photoresist developers , some of which are strong bases.
***Leave the hot piranha solution in an open container until cool on one of the SMFL wetbenches.
***Do not store piranha. Mix only enough fresh solution for each use. Excess solutions should be disposed via the drain (once cool), followed by flushing with copious amounts of water.
***Mixing hot piranha with organic compounds may cause an a very violent reaction. This includes materials such as acetone, photoresist, isopropyl alcohol, and nylon.

*The SMFL has a large number of chemicals available for use in the facility. There may be times when a chemical needed for a project is not stocked in the SMFL.
*Before any chemical can be brought in, it '''must''' be signed off by the SMFL. This applies to all users whether they are internal or external.
*The http://smfl.microe.rit.edu/forms/imported_chemicals.pdf SMFL Imported Chemical Worksheet needs to be filled out and submitted with the MSDS before the chemicals can be brought into the lab.

Fill out sections 1,2 & 6 and bring to T. Grimsley in 17-2175 for review and signoff.